Digital Twin Enabled 6G Radio Testing: Concepts, Challenges and Solutions

The sixth-generation (6G) mobile communication is envisioned to be an all connected radio system, which covers the vertical expansion from ground-based networks to spaceborne networks, and the horizontal expansion from ultra-short range to ultra-long range communications. As a result, the number of radio devices and associated test cases and scenarios will grow exponentially, making field trials (i.e., testing in real deployment scenarios) unfeasible due to the cost and time concerns. A digital twin (DT) concept can be adopted to reproduce the field trials, enabling 6G radio testing and development in controllable and repeatable laboratory conditions where the radio devices and network should operate as if they would in real-world conditions. This article investigates DT-enabled 6G radio testing. First, the concept of DT for radio testing is introduced, including information on how DT can capture the radio environment with unique propagation features. Next, three state-of-the-art emulation setups of DT for radio testing are explained. The article also covers challenges introduced by new 6G radio technologies for the DT-enabled 6G radio testing, including potential solutions to tackle those challenges.